(3x²y)²·(-15xy³)÷(-9x4次方y²)-搜答案-大师作文网

解题思路：提取公因式进行分解解题过程：附件最终答案：略

因为x-2根号xy-15y=0,左右同除以根号xy,所以得到根号（x/y)-2-15根号(y/x)=0如果你看的不习惯,可以设根号(y/x)=t,则根号（x/y)=1/t,(t>0)因此,(1/t)-

2分之3X^(3)Y-6X^(2)Y^(2）+9XY^(3)

原式=x²-y²-(4x²y²+12xy²+9y²)=x²-y²-4x²y²-12xy²-

xy(xy+1)+(xy+3)-2(x+y+1/2)-(x+y-1)^2=xy(xy+1)+(xy+1)+2-2(x+y)-1-[(x+y)^2-2(x+y)+1]=(xy+1)^2+2-2(x+y)

x^2-xy-6y^2+3xy+y+2

3xy是3x原式=(x-3y)(x+2y)+3x+y+2十字相乘x-3y2×x+2y1所以原式=(x-3y+2)(x+2y+1)

解题思路：本题主要利用完全平方公式进行因式分解即可求出结果解题过程：解:x²－6xy＋9y²=(x-3y)2

原式=-3x³y³+6x^4y^4+4x²y³*2x²y=-3x³y³+6x^4y^4+8x^4y^4=-3x³y&su

3xy[2xy-x(y-2)+x-1]=3xy(2xy-xy+2x+x-1)=3xy(xy+3x-1)=3x^2y^2+9x^2y-3xy

3xy[2xy-x（y-2）+x]＝3xy[2xy-xy+2x+x]=3xy(xy+3x)=3x²y²+9x²y

(-3x^y+2xy)-(4x^+xy)=-3x^y+2xy-4x^-xy=-3x^y+xy-4x^所以填上-3x^y+xy-4x^

解题思路：将原方程右边分解因式为（x-4y)(x+y)=0,可得x=4y或x=-y,进而可求出x与y的比值。解题过程：解：∵x2-3xy-4y2=0∴（x-4y)(x+y)=0∴x=4y或x=-y∵x

x^3y(-4y)^2+(-7xy)^2*(-xy)-5xy^3*(-3x)^2=16x^3y^3-49x^3y^3-45^3y^3=-78x^3y^3如果本题有什么不明白可以追问,

原式(-xy/3)²*[xy(2x-y)-2x(xy-y²)]=(x²y²/9)(2x²y-xy²-2x²y+2xy²)

∵x-y=4xy，∴2x+3xy-2yx-2xy-y=2(x-y)+3xyx-y-2xy=8xy+3xy4xy-2xy=112．故答案为：112．

（7x+4y+xy）-6（5/6y+x-xy）=7x+4y+xy-5y-6x+6xy=x-y+7xy=5+7×(-3)=-16

(3xy)²·(x²+xy-y²)-3xy(3x³y+3x²y²-xy³)=3xy(3x^3y+3x^2y^2-3xy^3-3x&

因为：xy=(x-10)(y+1)→xy=xy+x-10y-10①xy=(x-15)(y+3)→xy=+3x-15y-45②由①、②得：x=10y+10③x=5y+15④将③‐④得：10y+

原式=-x²y+2xy²+2x²y²-4xy³-3x³+27x³y-18x²y²+2x²y-18x&

原式=(x³y-3xy²+3xy²)·（-2xy）+2x⁴y²-x³y³=x³y·（-2xy）+2x⁴y&